// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2017 Gael Guennebaud <gael.guennebaud@inria.fr>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#if !defined(EIGEN_PARSED_BY_DOXYGEN)

// This file is automatically included twice to generate const and non-const versions

#ifndef EIGEN_INDEXED_VIEW_METHOD_2ND_PASS
#define EIGEN_INDEXED_VIEW_METHOD_CONST const
#define EIGEN_INDEXED_VIEW_METHOD_TYPE ConstIndexedViewType
#else
#define EIGEN_INDEXED_VIEW_METHOD_CONST
#define EIGEN_INDEXED_VIEW_METHOD_TYPE IndexedViewType
#endif

#ifndef EIGEN_INDEXED_VIEW_METHOD_2ND_PASS
protected:
// define some aliases to ease readability

template <typename Indices> struct IvcRowType : public internal::IndexedViewCompatibleType<Indices, RowsAtCompileTime>
{
};

template <typename Indices> struct IvcColType : public internal::IndexedViewCompatibleType<Indices, ColsAtCompileTime>
{
};

template <typename Indices> struct IvcType : public internal::IndexedViewCompatibleType<Indices, SizeAtCompileTime>
{
};

typedef typename internal::IndexedViewCompatibleType<Index, 1>::type IvcIndex;

template <typename Indices> typename IvcRowType<Indices>::type ivcRow(const Indices& indices) const
{
    return internal::makeIndexedViewCompatible(indices, internal::variable_if_dynamic<Index, RowsAtCompileTime>(derived().rows()), Specialized);
}

template <typename Indices> typename IvcColType<Indices>::type ivcCol(const Indices& indices) const
{
    return internal::makeIndexedViewCompatible(indices, internal::variable_if_dynamic<Index, ColsAtCompileTime>(derived().cols()), Specialized);
}

template <typename Indices> typename IvcColType<Indices>::type ivcSize(const Indices& indices) const
{
    return internal::makeIndexedViewCompatible(indices, internal::variable_if_dynamic<Index, SizeAtCompileTime>(derived().size()), Specialized);
}

public:
#endif

template <typename RowIndices, typename ColIndices> struct EIGEN_INDEXED_VIEW_METHOD_TYPE
{
    typedef IndexedView<EIGEN_INDEXED_VIEW_METHOD_CONST Derived, typename IvcRowType<RowIndices>::type, typename IvcColType<ColIndices>::type> type;
};

// This is the generic version

template <typename RowIndices, typename ColIndices>
typename internal::enable_if<internal::valid_indexed_view_overload<RowIndices, ColIndices>::value &&
                                 internal::traits<typename EIGEN_INDEXED_VIEW_METHOD_TYPE<RowIndices, ColIndices>::type>::ReturnAsIndexedView,
                             typename EIGEN_INDEXED_VIEW_METHOD_TYPE<RowIndices, ColIndices>::type>::type
operator()(const RowIndices& rowIndices, const ColIndices& colIndices) EIGEN_INDEXED_VIEW_METHOD_CONST
{
    return typename EIGEN_INDEXED_VIEW_METHOD_TYPE<RowIndices, ColIndices>::type(derived(), ivcRow(rowIndices), ivcCol(colIndices));
}

// The following overload returns a Block<> object

template <typename RowIndices, typename ColIndices>
typename internal::enable_if<internal::valid_indexed_view_overload<RowIndices, ColIndices>::value &&
                                 internal::traits<typename EIGEN_INDEXED_VIEW_METHOD_TYPE<RowIndices, ColIndices>::type>::ReturnAsBlock,
                             typename internal::traits<typename EIGEN_INDEXED_VIEW_METHOD_TYPE<RowIndices, ColIndices>::type>::BlockType>::type
operator()(const RowIndices& rowIndices, const ColIndices& colIndices) EIGEN_INDEXED_VIEW_METHOD_CONST
{
    typedef typename internal::traits<typename EIGEN_INDEXED_VIEW_METHOD_TYPE<RowIndices, ColIndices>::type>::BlockType BlockType;
    typename IvcRowType<RowIndices>::type actualRowIndices = ivcRow(rowIndices);
    typename IvcColType<ColIndices>::type actualColIndices = ivcCol(colIndices);
    return BlockType(
        derived(), internal::first(actualRowIndices), internal::first(actualColIndices), internal::size(actualRowIndices), internal::size(actualColIndices));
}

// The following overload returns a Scalar

template <typename RowIndices, typename ColIndices>
typename internal::enable_if<internal::valid_indexed_view_overload<RowIndices, ColIndices>::value &&
                                 internal::traits<typename EIGEN_INDEXED_VIEW_METHOD_TYPE<RowIndices, ColIndices>::type>::ReturnAsScalar,
                             CoeffReturnType>::type
operator()(const RowIndices& rowIndices, const ColIndices& colIndices) EIGEN_INDEXED_VIEW_METHOD_CONST
{
    return Base::operator()(internal::eval_expr_given_size(rowIndices, rows()), internal::eval_expr_given_size(colIndices, cols()));
}

#if EIGEN_HAS_STATIC_ARRAY_TEMPLATE

// The following three overloads are needed to handle raw Index[N] arrays.

template <typename RowIndicesT, std::size_t RowIndicesN, typename ColIndices>
IndexedView<EIGEN_INDEXED_VIEW_METHOD_CONST Derived, const RowIndicesT (&)[RowIndicesN], typename IvcColType<ColIndices>::type>
operator()(const RowIndicesT (&rowIndices)[RowIndicesN], const ColIndices& colIndices) EIGEN_INDEXED_VIEW_METHOD_CONST
{
    return IndexedView<EIGEN_INDEXED_VIEW_METHOD_CONST Derived, const RowIndicesT(&)[RowIndicesN], typename IvcColType<ColIndices>::type>(
        derived(), rowIndices, ivcCol(colIndices));
}

template <typename RowIndices, typename ColIndicesT, std::size_t ColIndicesN>
IndexedView<EIGEN_INDEXED_VIEW_METHOD_CONST Derived, typename IvcRowType<RowIndices>::type, const ColIndicesT (&)[ColIndicesN]>
operator()(const RowIndices& rowIndices, const ColIndicesT (&colIndices)[ColIndicesN]) EIGEN_INDEXED_VIEW_METHOD_CONST
{
    return IndexedView<EIGEN_INDEXED_VIEW_METHOD_CONST Derived, typename IvcRowType<RowIndices>::type, const ColIndicesT(&)[ColIndicesN]>(
        derived(), ivcRow(rowIndices), colIndices);
}

template <typename RowIndicesT, std::size_t RowIndicesN, typename ColIndicesT, std::size_t ColIndicesN>
IndexedView<EIGEN_INDEXED_VIEW_METHOD_CONST Derived, const RowIndicesT (&)[RowIndicesN], const ColIndicesT (&)[ColIndicesN]>
operator()(const RowIndicesT (&rowIndices)[RowIndicesN], const ColIndicesT (&colIndices)[ColIndicesN]) EIGEN_INDEXED_VIEW_METHOD_CONST
{
    return IndexedView<EIGEN_INDEXED_VIEW_METHOD_CONST Derived, const RowIndicesT(&)[RowIndicesN], const ColIndicesT(&)[ColIndicesN]>(
        derived(), rowIndices, colIndices);
}

#endif  // EIGEN_HAS_STATIC_ARRAY_TEMPLATE

// Overloads for 1D vectors/arrays

template <typename Indices>
typename internal::enable_if<IsRowMajor && (!(internal::get_compile_time_incr<typename IvcType<Indices>::type>::value == 1 ||
                                              internal::is_valid_index_type<Indices>::value)),
                             IndexedView<EIGEN_INDEXED_VIEW_METHOD_CONST Derived, IvcIndex, typename IvcType<Indices>::type>>::type
operator()(const Indices& indices) EIGEN_INDEXED_VIEW_METHOD_CONST
{
    EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
    return IndexedView<EIGEN_INDEXED_VIEW_METHOD_CONST Derived, IvcIndex, typename IvcType<Indices>::type>(derived(), IvcIndex(0), ivcCol(indices));
}

template <typename Indices>
typename internal::enable_if<(!IsRowMajor) && (!(internal::get_compile_time_incr<typename IvcType<Indices>::type>::value == 1 ||
                                                 internal::is_valid_index_type<Indices>::value)),
                             IndexedView<EIGEN_INDEXED_VIEW_METHOD_CONST Derived, typename IvcType<Indices>::type, IvcIndex>>::type
operator()(const Indices& indices) EIGEN_INDEXED_VIEW_METHOD_CONST
{
    EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
    return IndexedView<EIGEN_INDEXED_VIEW_METHOD_CONST Derived, typename IvcType<Indices>::type, IvcIndex>(derived(), ivcRow(indices), IvcIndex(0));
}

template <typename Indices>
typename internal::enable_if<(internal::get_compile_time_incr<typename IvcType<Indices>::type>::value == 1) &&
                                 (!internal::is_valid_index_type<Indices>::value) && (!symbolic::is_symbolic<Indices>::value),
                             VectorBlock<EIGEN_INDEXED_VIEW_METHOD_CONST Derived, internal::array_size<Indices>::value>>::type
operator()(const Indices& indices) EIGEN_INDEXED_VIEW_METHOD_CONST
{
    EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
    typename IvcType<Indices>::type actualIndices = ivcSize(indices);
    return VectorBlock<EIGEN_INDEXED_VIEW_METHOD_CONST Derived, internal::array_size<Indices>::value>(
        derived(), internal::first(actualIndices), internal::size(actualIndices));
}

template <typename IndexType>
typename internal::enable_if<symbolic::is_symbolic<IndexType>::value, CoeffReturnType>::type operator()(const IndexType& id) EIGEN_INDEXED_VIEW_METHOD_CONST
{
    return Base::operator()(internal::eval_expr_given_size(id, size()));
}

#if EIGEN_HAS_STATIC_ARRAY_TEMPLATE

template <typename IndicesT, std::size_t IndicesN>
typename internal::enable_if<IsRowMajor, IndexedView<EIGEN_INDEXED_VIEW_METHOD_CONST Derived, IvcIndex, const IndicesT (&)[IndicesN]>>::type
operator()(const IndicesT (&indices)[IndicesN]) EIGEN_INDEXED_VIEW_METHOD_CONST
{
    EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
    return IndexedView<EIGEN_INDEXED_VIEW_METHOD_CONST Derived, IvcIndex, const IndicesT(&)[IndicesN]>(derived(), IvcIndex(0), indices);
}

template <typename IndicesT, std::size_t IndicesN>
typename internal::enable_if<!IsRowMajor, IndexedView<EIGEN_INDEXED_VIEW_METHOD_CONST Derived, const IndicesT (&)[IndicesN], IvcIndex>>::type
operator()(const IndicesT (&indices)[IndicesN]) EIGEN_INDEXED_VIEW_METHOD_CONST
{
    EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
    return IndexedView<EIGEN_INDEXED_VIEW_METHOD_CONST Derived, const IndicesT(&)[IndicesN], IvcIndex>(derived(), indices, IvcIndex(0));
}

#endif  // EIGEN_HAS_STATIC_ARRAY_TEMPLATE

#undef EIGEN_INDEXED_VIEW_METHOD_CONST
#undef EIGEN_INDEXED_VIEW_METHOD_TYPE

#ifndef EIGEN_INDEXED_VIEW_METHOD_2ND_PASS
#define EIGEN_INDEXED_VIEW_METHOD_2ND_PASS
#include "IndexedViewMethods.h"
#undef EIGEN_INDEXED_VIEW_METHOD_2ND_PASS
#endif

#else  // EIGEN_PARSED_BY_DOXYGEN

/**
  * \returns a generic submatrix view defined by the rows and columns indexed \a rowIndices and \a colIndices respectively.
  *
  * Each parameter must either be:
  *  - An integer indexing a single row or column
  *  - Eigen::all indexing the full set of respective rows or columns in increasing order
  *  - An ArithmeticSequence as returned by the Eigen::seq and Eigen::seqN functions
  *  - Any %Eigen's vector/array of integers or expressions
  *  - Plain C arrays: \c int[N]
  *  - And more generally any type exposing the following two member functions:
  * \code
  * <integral type> operator[](<integral type>) const;
  * <integral type> size() const;
  * \endcode
  * where \c <integral \c type>  stands for any integer type compatible with Eigen::Index (i.e. \c std::ptrdiff_t).
  *
  * The last statement implies compatibility with \c std::vector, \c std::valarray, \c std::array, many of the Range-v3's ranges, etc.
  *
  * If the submatrix can be represented using a starting position \c (i,j) and positive sizes \c (rows,columns), then this
  * method will returns a Block object after extraction of the relevant information from the passed arguments. This is the case
  * when all arguments are either:
  *  - An integer
  *  - Eigen::all
  *  - An ArithmeticSequence with compile-time increment strictly equal to 1, as returned by Eigen::seq(a,b), and Eigen::seqN(a,N).
  *
  * Otherwise a more general IndexedView<Derived,RowIndices',ColIndices'> object will be returned, after conversion of the inputs
  * to more suitable types \c RowIndices' and \c ColIndices'.
  *
  * For 1D vectors and arrays, you better use the operator()(const Indices&) overload, which behave the same way but taking a single parameter.
  *
  * See also this <a href="https://stackoverflow.com/questions/46110917/eigen-replicate-items-along-one-dimension-without-useless-allocations">question</a> and its answer for an example of how to duplicate coefficients.
  *
  * \sa operator()(const Indices&), class Block, class IndexedView, DenseBase::block(Index,Index,Index,Index)
  */
template <typename RowIndices, typename ColIndices> IndexedView_or_Block operator()(const RowIndices& rowIndices, const ColIndices& colIndices);

/** This is an overload of operator()(const RowIndices&, const ColIndices&) for 1D vectors or arrays
  *
  * \only_for_vectors
  */
template <typename Indices> IndexedView_or_VectorBlock operator()(const Indices& indices);

#endif  // EIGEN_PARSED_BY_DOXYGEN
